/*
 * =============================================================================
 * Copyright© by Benjamin Sempere,
 * All rights reserved.
 * =============================================================================
 * Author  : Benjamin Sempere
 * E-mail  : benjamin@sempere.org
 * Homepage: www.sempere.org
 * =============================================================================
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package org.sempere.gwt.toolbox.remoting.client.rpc.callback;

import org.sempere.gwt.toolbox.core.client.common.ExceptionHandler;

import com.google.gwt.core.client.GWT;

public abstract class AbstractCallback<T> implements Callback<T> {

	// Execution context (useful for passing extra data to this callback)
	protected Object context;

	// Exception handler used when an error occurred on an asynchronous call
	private ExceptionHandler exceptionHandler = new CallbackExceptionHandler();

	/**
	 * Default class constructor
	 */
	public AbstractCallback() {
	}

	/**
	 * Define a callback with an execution context
	 * 
	 * @param context execution context
	 */
	public AbstractCallback(Object context) {
		this.context = context;
	}

	/**
	 * Method invoked when no error occurred during asynchronous call
	 * 
	 * @param result asynchronous call result
	 */
	public void onSuccess(T result) {
		GWT.log("Object [" + result + "] was received by the callback with name [" + this.getCallbackName() + "].", null);
	}

	/**
	 * Method invoked when an error occurred during asynchronous call
	 * 
	 * @param throwable exception encountered during asynchronous call
	 */
	public void onFailure(Throwable throwable) {
		GWT.log("An exception was received by the callback with name [" + this.getCallbackName() + "].", throwable);
		this.exceptionHandler.handleException(this.getErrorMessage(), throwable);
	}

	/**
	 * Return custom error message
	 * 
	 * @return String
	 */
	public abstract String getErrorMessage();

	public Object getContext() {
		return context;
	}

	// ********************************************************************************
	//
	// Setters for dependency injection
	//
	// ********************************************************************************

	public void setExceptionHandler(ExceptionHandler exceptionHandler) {
		this.exceptionHandler = exceptionHandler;
	}
}
